2.4-2.7 quiz

At which time after clear-cutting does the ecosystem exhibit the greatest species richness?

100 years

Which of the following was the number of finches in the population with a beak size of 10.2 mm in 1978?

12

The pH at which 50 percent of the Daphnia survive after 2 hours of exposure can be predicted from the data. This pH is closest to

4.5

On the basis of the data, the best prediction of the pH of the water in which Daphnia normally are found in the wild is

7

The graphs above show the population size and distribution of beak sizes in a finch population on the island of Daphne Major in the Galapagos in 1976 and 1978. Smaller-beaked finches are better suited for eating grasses and small seeds. Larger-beaked finches are better suited for cracking larger seeds and nuts. In 1977 a drought took place and the vegetation of the island was affected by the lack of rain. Which of the following was the average beak size of finches on the island of Daphne Major in 1976?

9.5 mm

Which of the following best shows the process of evolution?

A population of mosquitoes develops resistance to a pesticide.

Little is known about Africa's elusive aardvarks, but new research says they are vulnerable to climate change like many other species.Hotter temperatures are taking their toll on the aardvark, whose diet of ants and termites is becoming scarcer in some areas because of reduced rainfall. The aardvark, which lives in many parts of sub-Saharan Africa, is identified as an animal of "least concern" on an international "red list" of threatened species. There are no indications that the population is changing significantly in southern Africa, though it is speculated that numbers may be declining elsewhere because of habitat destruction, the bushmeat trade and other factors. Which of the following best identifies the author's claim?

Aardvarks are a keystone species and their decline could have a trophic cascade effect on the ecosystem.

Which of the following claims is best supported by the data in the graph "Number of Plant Species"?

After the volcanic eruption, pioneer species colonized the area and the ecosystem began to undergo succession.

Which of the following explanations is best supported by the data shown in the map above?

Animals migrate seasonally to mate and to find food in different habitats.

Based on the data in the table, which ecosystem is in the earliest stages of succession?

Ecosystem B

The diagrams above show the range of tolerance for soil moisture content for two different species of terrestrial invertebrate: Species 1 and Species 2. The ranges represented are for each species where it occurs alone. Soil moisture content is a limiting factor for both species. If populations of both species are placed together in a new location, which of the following diagrams represents the most likely actual (realized) ranges of the species' distribution of individuals with respect to soil moisture content after five generations?

Graph D with curves slightly overlapping

Living organisms must acquire energy from their environment. Examples of adaptations that help organisms acquire this energy include which of the following? I. The dark, heat-absorbing coloration of a reptile. II. The fangs and claws of a lion III. The light coloration of a peppered moth

I and II only

Based on the diagram above, in which stage are most species present considered pioneer species?

II

A research team monitoring a local freshwater ecosystem noticed that over the past few years the otter population had declined significantly, while the populations of other species remained fairly constant. After running tests, the research team determined that mercury levels in invertebrates and small fish in the ecosystem were very high. In this ecosystem, what role did the otters occupy?

Indicator Species

Which of the following best describes the role of moss in the transition to stage III of the process?

It breaks down rock and adds organic nutrients to the soil.

The data shown were collected in a laboratory experiment in which the effect of pH on the survival of water fleas (Daphnia pulex) was examined. In each trial, 40 live water fleas were added to a solution with the pH as indicated. After two hours, observations were made to determine the number of fleas remaining alive in the sample. Results are presented in the table and in graphical form below. How would including a control group be useful in this experiment?

It would provide a reference for the effects of random environmental factors

A North Carolina timber company proposes to clear-cut 45 hectares of oak-hickory deciduous forest in the Appalachian Mountains. The company has said that the forest will regrow naturally, and 50 years after the clear-cutting the company plans to harvest again, cutting all the oaks and hickories that have at least a 40-centimeter diameter. A local citizens' group claims that this is not a realistic plan. Which of the following, if true, best supports the claim of the citizens' group?

Oak and hickory are late-successional species; pioneer species will dominate for many decades before the oaks and hickories are reestablished.

Based on the data shown in the graph, when would the species richness of the ecosystem have been the lowest?

One to four years after the volcanic eruption

On the coast of Oregon, mussels cover most of the rocky shoreline. Two mussel predators include Pisaster (ochre stars) and Nucella (whelks). A sixty-day removal study was conducted, and the results are presented in the graph. Which of the following conclusions is best supported by the data in the graph?

Pisaster is a keystone species, because when Nucella was removes the proportion of live mussels was similar to the control

Based on the data shown in the graph, which of the following events occurred after the glacial retreat?

Primary succession

The diagram below shows the change in an ecosystem over time. Which of the following best identifies and describes the process that is illustrated in the diagram above?

Primary succession, because the process in the diagram begins with bare rock.

Based on the data shown in the graph, which of the following best describes how ecologists could determine when this ecosystem is approaching a climax community?

Record the number and type of producers present every year after the eruption

Which of the following is the best example of a keystone species?

Sea otter

Which of the following best describes why secondary succession generally occurs more quickly than primary succession?

Secondary succession takes place in areas that already have soil and nutrients in place, whereas primary succession occurs in areas that lack soil.

Which tree species grows best with full sunlight?

Sweet gum

A one-hectare pond is sampled in early September. The sample yields 1 small catfish as well as 17 benthic invertebrates that represent 10 species. If the pond is resampled a year later, which of the following would best indicate that the pond had been adversely affected by adjacent development?

The biodiversity of the pond has decreased

Which of the following best describes the frog species' range of tolerance to acidic conditions?

The frogs can tolerate a pH between 4.5 and 6

Scientists are interested in determining the impact of the construction of a hydroelectric dam on a population of salmon that live downstream of a populated area. They measure the health of the salmon population in its current state, several years after the dam was constructed. Which of the following would be the best to use as a control in this study?

The health of the salmon population prior to any dam construction

A major factor contributing to the large dead zone this year is the high amount of spring rainfall in many parts of he Mississippi River watershed, which led to record high river flows and much larger nutrient loading to the Gulf of Mexico. This past May, discharge in the Mississippi and Atchafalaya rivers was about 67 percent above the long-term average between 1980 and 2018. The latest National Climate Assessment predicts an increase in the frequency of very heavy precipitation events in the Midwest, Great Plains, and Southeast regions, which would impact nutrient input to the northern Gulf of Mexico and the size of the hypoxic zone." News release adapted from the United States Geological Survey Which of the following best identifies the author's claim?

The increased rainfall events in the United States are decreasing the tolerance of fish and other marine species in the Gulf of Mexico because of a decreased concentration of oxygen.

The graph below shows the change in sea level from the Cambrian period to today compared to today's sea level. Which of the following statements correctly describes the trends seen in the data?

The lowest sea level occurred during the Paleogene period

The Devils Hole pupfish is one of the world's rarest fishes, spending most of its life in the top few meters of very warm waters of a cavern located in the middle of the Mojave Desert. Devils Hole, a geologic pool, is the only naturally occurring habitat for the endangered Devils Hole pupfish. This fish's habitat is one of the smallest natural ranges known for any vertebrate. Devils Hole is an extreme environment, with water temperatures and dissolved oxygen concentrations near the lethal limits for most fish species. Which of the following statements best explains why the Devils Hole pupfish are able to live in this environment?

The pupfish are well adapted to the habitat of Devils Hole and can thrive in conditions that are outside of the range of tolerance for most other species.

Which of the following statements best explains the changes in the size and composition of the population of finches after the drought?

The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment.

The table below shows measurements of the beak size of a sample of ten ground finches on each of two islands in the Galápagos archipelago. The two islands are about ten kilometers apart, and all the birds are the same species. Given that beak size is genetically determined, which of the following hypotheses is the most likely explanation for the differences in data between the islands?

The types of food found on the two islands exert selective pressure on beak size

A student reads that nanosilver particles are used in cosmetics to allow nutrients to penetrate deeper into the skin. When the cosmetics are washed off, the nanosilver particles can enter freshwater ecosystems. These particles may decrease survival in many aquatic organisms. The student determines that Daphnia magna, a tiny freshwater crustacean widely found in North America, might make a good test subject for an experiment. Which statement below is the most likely testable hypothesis based on the information provided?

When the concentration of nanosilver particles in water is increased, the population of Daphnia magna will decrease.

Bull trout use a bewildering array of strategies to aid in their survival, from remaining in streams their whole lives, like rainbow trout, to spending part of their lives in the ocean before returning to streams to spawn, just as salmon do. Bull trout are present in only one of two neighboring rivers in the Olympic peninsula, Washington state, and in this one (the Elwha River), where two large dams were removed. Dam removal resulted in massive outflow of sediments, reducing the clarity of the water and also building up a large delta and expanding the size of the estuary at the mouth of the Elwha Of additional interest is the long-term response of bull trout to the additional habitat opened up above the former dams. Which of the following best identifies the author's claim?

bull trout are unable to live in high sediment loaded waters and migrated to avoid the conditions introduced during dam deconstruction

In North America, native pollinators often increase the quantity and quality of crops of native plants that are insect pollinated more effectively than European honeybees do. The most likely reason for the phenomenon is that native pollinators

have coevolved with native plant species

In England approximately 250 years ago, the peppered moth had light-colored wing patterns that camouflaged them against the light-colored trees. Over time in urban areas, the number of peppered moths with dark-colored wings increased as pollution from the Industrial Revolution darkened the trees the moths rested on. Which of the following statements best describes how the moths adapted to the new environment over time?

the moths adapted to the new environment by changes in the genetics of the population.